Caring for Carnivorous Plants

The term ‘Carnivorous’ means ‘meat / eating’, and refers here to plants that trap and digest flies, beetles and other small insects. These plants are also called ‘insectivorous’, or ‘insect eating’, and are sold by specialist nurseries and larger garden centres.

Carnivorous plants are found all over the world, usually in acid peat bogs or heavy volcanic clay soils, which lack nutrients, especially nitrogen. To make up for it, they trap insects on or in their leaves, produce special juices, or enzymes, to dissolve the insects’ bodies, then digest the resulting liquid directly into the leaf tissues.

Hinged-leaf plants

venus-fly-trap

Hinged-leaf plants have spiny-edged leaves made of two blades, hinged at the midrib. The most popular house plant is the Venus Fly Trap, from the Carolina swamps in America. Each of its jaw-like leaves has red, gland-bearing hairs and three ‘trigger’ hairs on the surface of each leaf blade. If an insect touches the trigger hairs, the leaf snaps shut, often in less than a second, and it then remains shut for several days, until only the insect’s skeleton is left.

Sticky-leaved plants

Sundews have tentacle-like hairs all over the upper leaf surfaces. At the tip of each hair is a tiny, club-shaped gland which gives out, or secretes, sticky fluid to attract insects. Once an insect lands on the leaf and sticks to the fluid, its struggle to escape causes other, nearby hairs to bend over and further enmesh it. The leaf slowly folds round the insect and digests the body.

Pitcher plants

pitcher-plantPitcher plants wait patiently for insects, attracted by nectar, to enter their water-filled ‘pitchers’. The insects can’t climb out because the sides of the ‘pitcher’, actually a modified leaf, are covered with many stiff, downward-pointing hairs – some pitchers even have lids. The insects soon drown, and enzymes released into the water by the plant help it digest the remains.

Growing carnivorous plants

There are hardy, half-hardy and tender species, so needs vary. Cool greenhouses or conservatories are ideal for most types, but a bright, cool room is fine. Individual Plant Cards give details, but here is a general guide.

Pots and potting mixtures

Use moisture-retaining but free-draining potting mixture, for example; equal parts of peat and sphagnum moss; peat and perlite; or peat and sand. Or use lime-free potting mixture, such as for Rhododendrons, with perlite, vermiculite, sphagnum moss or peat added, for drainage.

Use alpine half-pans for small plants, or ordinary pots. Carnivorous plants are slow-growing, so if repotting, use a pot only a little larger than the previous one.

Watering and feeding

All carnivorous plants need generous watering in spring and summer, and like standing in a water-filled saucer or dish. Tropical species, such as Nepenthes, need generous watering all year round; keep hardy and half-hardy types just slightly damp in winter. Place dead flies or tiny bits of raw meat on to the leaves, or spray occasionally with foliar feed. Don’t add fertilizer, or feed with meat or flies if a feeding leaf is still shut.

Temperature, humidity, light and air Tropical types need year-round warmth. 18°-30°C (65°-85°F), while the others like cool winters, 4.5°C (40°F) or less, and ordinary summer temperatures. All need high humidity. Resting them in a container of water helps, as does daily mist spraying or growing them in Wardian cases or terrariums.

  • Most carnivorous plants need bright, indirect light, and Nepenthes need protection from sun all year round. All, especially non-tropical types, need good ventilation in spring and summer.
  • A cool, bright conservatory or greenhouse is an ideal site for most carnivorous plants, but shield them from direct sun.
  • Most carnivorous plants enjoy high humidity combined with a free-draining moss- or peat-based compost. Stand pots in a saucer of moist pebbles, or mist spray frequently.
  • Carnivorous plants are more fascinating and curious than beautiful, and quite a challenge to the house plant enthusiast. Here are some tips on how to grow them.
  • The elegant Huntsman’s I kurn can attain a considerable height. Fond of summer humidity, it likes a cool winter rest.
  • The Venus Fly Trap is a challenging plant to grow successfully in the home, thriving in high humidity and bright, filtered light.

Where did the name Sundew come from?

People first thought that the droplets of fly-catching liquid were dew, and that the plant could retain dew in sunlight, while that on other plants evaporated. Sundew was once thought to have magical properties, and was used by herbalists and alchemists.

I’m growing Huntsman’s Cup on my patio. Is there anything special I should do?

huntsman's-cup

Cover the potting mixture with a layer of moss. In winter, fix a pane of glass horizontally, 7.5cm (3in) above the plant. This protects it from hard frost and snow.

What if I gave Venus Fly Trap a piece of grit to eat?

You can’t fool these plants! They don’t react when drops of water fall on their leaves, and though they will snap shut round a tiny pebble, they soon open again, for wind or rain to remove the offending matter.

Carnivorous plants to try

  • Alpine Butterwort (Pinguicala cdpind)
  • Bog Violet (Pinguicula tulgaris)
  • Cobra Plant Martino mid calttumici)
  • European Butterwort (Pinguicula granthlb)
  • Great Sundew (Drosera Linglieci)
  • Huntsman’s Cup
  • Lace Trumpets
  • Mexican Butterwort
  • Pitcher Plant
  • Round-leaved Sundew
  • Venus Fly Trap

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